NUTRIENT NEUTRALITY

Simple solutions to a big problem for developers.

watercourses.

Increased levels of nutrients (especially nitrogen and phosphorous) in water courses create an overabundance of algae leading to algal booms and lowoxygen water that eventually kills essential water habitats. The sources of these nutrients are largely mains and off-grid treatment works and agricultural and industrial processes.

Scale Of The Problem

Since 2020, Natural England (NE) have issued guidance to 74 Local Planning Authorities (LPA), advising that they are unable to grant planning permission unless the applicant can demonstrate that the development is ‘nutrient neutral’ i.e. will not increase the current phosphate or nitrate levels within the catchment areas of vulnerable watercourses. This has resulted in a significant number of applications being stalled within the planning system.

It is generally assumed that the guidance only impacts residential developments. However, this is not the case and includes developments relating to all types of overnight accommodation that will be connected to the mains and an off-grid treatment works. Other development applications will be considered on their individual merits, but generally, infrastructure that will increase agricultural intensification will also be impacted by the guidance.

Nutrient Calculations

The nutrient neutrality of a development is assessed on the existing and proposed land use changes, which will vary for each proposal. Each catchment area has its own nutrient budget calculator allowing the developer to establish the extent of work required to mitigate the impact of the nutrient effluent from their development.

Simple Mitigation Solutions

For smaller scale developments, a good place to start is looking at the proposed wastewater treatment works. Connecting to a package treatment system can significantly reduce the nutrient effluent from the development, making it nutrient neutral or reducing the level of mitigation required.

If further mitigation is required, this can often be achieved within the site boundary of the development proposal or within the applicant’s ownership boundary.

Our teams have been able to help clients overcome nutrient neutrality issues on their developments with relatively simple solutions including:

• Small scale woodland planting to create an orchard within a site area.

• Shrub planting to create hedgerows around the perimeter of a site boundary.

• Woodland planting along the access to a site. For larger scale developments, mitigation solutions may need to be found off-site or on land outside the applicant’s ownership.

OFF-SITE MITIGATION

Landowners within nutrient neutrality catchment areas have an opportunity to take land out of agricultural production and convert it to one which has a much lower nutrient leaching rate such as woodland, wetland, conservation grassland and heathland. This can be used to create ‘nutrient credits’ which can then be sold to developers to offset their nutrient load on the waterways - subject to approval by the LPA in conjunction with NE.

Given that the nutrient neutrality guidance covers 74 LPAs across England, and with landowners often looking for alternative income streams, the sale of nutrient credits is likely to become a very competitive marketplace.

Indeed, NE have secured agreements to revert arable land to create nutrient credits for developers within the Tees Valley to purchase.

These were recently auctioned at £1,825 each which will help to establish a market rate. However, the number of credits which each development needs is in doubt.

Current Uncertainty

Whilst applauded by many for this scheme, NE have been criticised for their production of a metric which over-estimates the additional nitrates from a development. At the time of writing some LPAs affected are looking to use substantially lower figures and clarity on the correct figure is needed before developers are likely to commit to mitigation strategies.

Professional Help And Guidance

At GSC Grays we seek to ensure that each mitigation strategy is proposed in line with your objectives. Once an appropriate mitigation scheme has been developed, a Habitats Regulations Assessment must be undertaken in consultation with NE who will need to be satisfied that the mitigation measures will achieve nutrient neutrality. The applications with which we have been involved are some of the first to be approved by NE and to be determined within the affected catchment areas.